The present invention relates to a magnetic tape cartridge, which has a sliding door for opening or closing the opening in order to extract a magnetic tape, and to a method for assembling the magnetic tape cartridge. It particularly relates to a magnetic tape cartridge, in which the lower half section and the upper half section can be mated easily in the assembly of the magnetic tape cartridge.
Generally speaking, in magnetic tape cartridges used as external storage medium for data backup of computers and the likes, a single reel wound with a magnetic tape is housed in a flat square like cartridge case, which is composed of the lower half section and the upper half section. When a magnetic tape cartridge is used, the tape loading mechanism of a record playback unit extracts the magnetic tape from the cartridge case and winds it around the reel placed in the record playback unit, thereby running the magnetic tape. It explains why an opening, which is for extracting the leading end of tape, is provided on the side of the cartridge case that houses a single reel of this type. This opening is normally closed to protect against the dust, and opened by the tape loading mechanism of a record playback unit only when either recording or playback is performed by the record playback unit.
Of the magnetic tape cartridges mentioned above, the magnetic tape cartridge represented by LTO (Linear Tape Open) standard is so arranged that the sliding door, which slides along inside the side wall of the cartridge case, opens or closes the opening. The sliding door is capable of sliding smoothly fitted in the guide channels, which are provided on both inner surfaces of the upper half section and the lower half section of the cartridge along their side walls. And a spring member imposes the force on the sliding door in the closing direction to close the opening except for the occasion when the magnetic tape cartridge is in use.
The assembly of the magnetic tape cartridge with a sliding door is performed in the following manner. The respective parts such as a reel and a claw for the protection of inadvertent erasing are set on the prescribed position of the lower half section, the spring member and the sliding door are inserted into the guide channel of the lower half section, and then the lower half section and the upper half section are mated. When the spring member is inserted into the guide channel, it is mounted compressed on the sliding door so as to impose the force on the sliding door in the closing direction.
However, before the lower half section and the upper half section are mated, the sliding door 102 is liable to lift from the guide channel 103 of the lower half section 105 by the force of the spring member 101 as shown in FIG. 29, since the spring member and the sliding door, which are inserted in the guide channel, are not restricted upward. Therefore, when the lower half section 105 and the upper half section are mated without any measures, there has been a problem that the sliding door 102 is not able to be inserted properly into the guide channel 103 of the lower half section or another guide channel of the upper half section (not shown).
Also before the lower half section and the upper half section are mated, the sliding door 102 inserted in the guide channel 103 is liable to fall in the opposite of the side wall 104, namely inside the cartridge case as shown with the arrow in FIG. 30, since the guide channel 103 of the lower half section 105 is carved shallow as shown in the figure. Therefore, there has been a problem, the same as described above, that the sliding door 102 is not able to be properly inserted into the guide channel 103 of the lower half section 105 or another guide channel of the upper half section (not shown).
The object of the present invention to address the above issues is to provide a magnetic tape cartridge, in which the mating of the lower half section and the upper half section can be easily performed and is applicable to automated assembly, when the magnetic tape cartridge having a sliding door is assembled.
The first aspect of the present invention to address the above issues is to provide a magnetic tape cartridge, comprising: an opening, which is positioned on a side of a cartridge case lying across a lower half section and an upper half section of the cartridge case, for extracting a magnetic tape; and a sliding door for opening or closing the opening, which is inserted in a closed position with force imposed by a spring member into lower and upper guides, which are placed in the lower half section and the upper half section of the cartridge case respectively, wherein the sliding door and the lower guide of the lower half section are equipped with an engagement device, which is capable of restricting the vertical displacement of the sliding door and guiding the sliding door in its moving direction freely.
As the magnetic tape cartridge is arranged so that the vertical displacement of the sliding door is restricted by the engagement device, which is provided in the lower guide of the lower half section. This way the engagement device prevents the sliding door inserted in the lower guide from lifting, when the magnetic tape cartridge is assembled. It follows that the sliding door can be inserted properly into the lower guide of the lower half section, when the magnetic tape cartridge is assembled. Therefore, when the lower half section and the upper half section are mated, the mistakes associated with mating can be prevented, since the mating of the lower half section and the upper half section is improved by inserting the sliding door into the lower and upper guide channels of the lower half section and the upper half section properly. The guide according to the appended claims includes all that guides the slide movement of the sliding door, not only the lower and upper guide channels carved on the lower half section and the upper half section but also the discontinuous projections and ribs provided for the half section, the side wall and the base of the half section.
The second aspect of the present invention provides a magnetic tape cartridge, comprising: an opening, which is positioned on a side of a cartridge case lying across a lower half section and an upper half section of the cartridge case, for extracting a magnetic tape; and a sliding door for opening or closing the opening, which is inserted in a closed position with force imposed by a spring member into lower and upper guides, which are placed in the lower half section and the upper half section of the cartridge case respectively, wherein a restriction device, which restrains the sliding door from falling in the direction normal to the plane of the sliding door, is provided along the lower guide of the lower half section.
Thus, when the magnetic tape cartridge is assembled, the sliding door can be mounted properly to the lower guide of the lower half section, since the sliding door inserted in the lower guide of the lower half section can be prevented from falling in the direction normal to its plane in contact with the restriction device provided along the lower guide. Therefore, if the lower half section and the upper half section are mated, the mistakes of mating can be prevented, since the sliding door can be inserted into the lower and upper guide channels of the lower half section and the upper half section properly to result in an easy mating. The guide referred to here includes all that guides the slide movement of the sliding door, not only the lower and upper guide channels carved on the lower half section and the upper half section but also the discontinuous projections and ribs provided on the half section, the side wall and the base of the half section.
The third aspect of the present invention provides a method for assembling a magnetic tape cartridge, which comprises an opening, which is positioned on a side of a cartridge case lying across a lower half section and an upper half section of the cartridge case, for extracting a magnetic tape, and a sliding door for opening or closing the opening, which is inserted in a closed position with force imposed by a spring member into lower and upper guides placed in the lower half section and the upper half section of the cartridge case respectively, the method comprises the steps of: inserting the sliding door into the lower guide of the lower half section while the spring member is compressed; and mating the upper half section with the lower half section while the spring member or the sliding door is pressed toward a base of the lower half section.
The spring member and the sliding door are prevented from lifting and falling when they are pressed toward the base of the lower half section by a pressing means such as a finger or a small stick. So the upper half section can be easily mated with the lower half section while the sliding door is guided by the lower guide of the lower half section. If the possible lowest part of the spring member or the sliding door, which stands on the lower half section, is held and pressed, the upper half section can be mated with the lower half section more securely, since the sliding door can be held until it is guided by the upper guide of the upper half section sufficiently.
As the guides, the examples such as a line channel on the inner base surfaces of the lower half section and the upper half section, or on the contrary projections on the inner surfaces of the lower half section and the upper half section along the sliding door are presented, which restrict the movement of the sliding door. Any types of springs such as a compression coil spring, extension coil spring, torsion coil spring, laminated spring, torsion bar, spiral spring, coned disk spring and leaf spring may be employed. Their materials are not limited to metals but resins may be used instead.
In the assembly method described above, it would be preferable to press the spring member or the sliding door to the side wall of the lower half section in parallel with pressing them toward the base of the lower half section, when the upper half section is mated with the lower half section.
Assembling like this allows the mating of the upper half section with the lower half section of the magnetic tape cartridge while keeping the spring member and the sliding door standing vertically beside the side wall of the lower half section, rendering its assembly easier and resulting in the prevention of mistakes related to the mating of the upper half section and the lower half section.
Especially when the spring member is set inside the sliding door, it will be possible to assemble the magnetic tape cartridge more reliably if the spring member is pressed to the side wall of the lower half section, since the inner part (the spring member) can also press the outer part (the sliding door) to the side wall of the lower half section.
The fourth aspect of the present invention provides a method for assembling a magnetic tape cartridge case, which includes the lower half section and the upper half section, the opening lying across the lower half section and the upper half section for extracting the leading end of the magnetic tape, the sliding door for opening or closing the opening beside the inside of the side wall of the case, and the spring member imposing the force on the sliding door in the closing direction. The sliding door is mounted to the lower and upper guides on the lower half section and the upper half section while the spring member imposes the force on the sliding door. The mounting of the sliding door of the magnetic tape cartridge is performed as follows.
The sliding door is inserted into the lower guide of the lower half section with the spring member imposing the force on the sliding door. Since the sliding door is liable to fall in the direction normal to its plane without any assistance, the end of the sliding door is supported by a supporting arm with the groove of V-shape. The lower half section and the upper half section are mated while supported by the supporting arm and then the supporting arm is removed for the subsequent steps.
The sliding door is thus supported by the supporting arm, inserted in the V-shape groove. The sliding door is pressed to the slopes of the V by the spring member, thereby interposed between the slopes of the V and standing against the groove of the supporting arm. Therefore, the sliding door is prevented from falling and the mating of the lower half section and the upper half section can be performed accurately and easily. Other parts not in contact with the sliding door are not necessarily of V-shape, for the object of the V-shape groove is to interpose the end of the sliding door with the two slopes and guide it to stand stably. For example, the root of V-shape groove may be rounded with fillet and the vicinity of the opening of the V may be permitted to be of a different shape.
As the guide of the sliding door described above, the examples such as a line channel on the inner surfaces of the lower half section and the upper half section, or on the contrary projections on the inner surfaces of the lower half section and the upper half section along the sliding door can be presented, which guide the movement of the sliding door. Any types of springs such as a compression coil spring, extension coil spring, torsion coil spring, spiral spring, and leaf spring may be employed. Their materials are not limited to metals but resins may be used instead.
In the assembly method described above, it would be preferable to provide the chamfering on the end of the sliding door, which fits to the slopes of the groove mentioned above, and perform the assembly in the following manner. The sliding door is mounted on the lower half section while the spring member imposes the force on the sliding door, the lower half section and the upper half section are mated by supporting the chamfered portion with the groove and then the assembly is continued after removing the supporting arm. The chamfering may be so arranged that the end surface has a flat portion or is of an edge with large chamfering. The circular contour of the end surface of sliding door may be an alternative instead of chamfering.
The chamfered portion of the sliding door is fitted into the V-shape groove deeply and the sliding door is thereby held upright, by assembling the magnetic tape cartridge this way. Therefore, the prevention of the falling of the sliding door is more ensured, which enables the accurate and easy mating of the lower half section and the upper half section.